Calipers



Oct. 29, 1935. LONG 2,018,731"

CALI PERS Filed Jan. 5, 1935 a A" Lam:-

Patented Oct. 29, 1935 j UNITED STATS OFFICE 2 Claims.

This invention relates to improvements in calipers and the main object is to provide an improved form of direct reading or micrometer caliper arranged so that it may be adjusted to a crankshaft of an automobile engine without removing the crankshaft and which will then indicate positively any flattening, unevenness or distortion in that shaft.

Another object is to provide an instrument of this kind comprising a pair of leg members pivotally connected at an intermediate point and bowed outwardly and tapered toward one of the ends of the leg assembly so that the points may fit up against the crankshaft bearing and engage the crankshaft at diametrically opposite points, the other ends of the leg members being also spread or bowed apart and one connected to an arm operating a sliding rack driving the pointer of an indicating device and the other being adjustably connected to a fixed anchor arm extended from the said indicating device whereby as the measuring ends of the legs are spread apart over the crankshaft the pointer will be moved over its scale.

5 Another object is to provide a device of this kind in a simple, inexpensive and conveniently used form.

With these and other objects in view the invention resides in the novel construction and ar- 30 rangement of parts as hereinafter fully set forth and claimed, reference being had tothe accompanying drawing wherein:

Figure l is a view of my invention in use, the automobile crankshaft, bearing, and crankcase 35 being shown in dotted lines.

Figure 2 is an enlarged lateral section through the indicating device alone.

Referring now with more particularity to the drawing my invention comprises a pair of leg 40 members designated generally at I and 2 and arranged in overlapping arrangement at intermediate points 3 whereby they are pivotally connected by a rivet or similar fastener 4.

ly of this pivot connection one end of each leg member is bowed oppositely outward and then inward as shown forming. arcuate work engaging ends 5 which are then tapered to a point 5 at their extremities. By this arrangement these points 50 6 may be placed right up against the upper hearing A of a conventional automobile engine crankcase B and will engage the crankshaft C at diametrically opposite points without removing the shaft from its bearings as would otherwise be 55 necessary. Only the oil pan and lower bearing Outwardcaps (not shown) are removed greatly simplifying the work.

Below or to the other side of the pivotal connection between the leg members these ends I and la of the legs are spread relatively widely apart 5 ated scale or dial II and a pointer I2 journaled 1O by its shaft I3 centrally through this scale. Within the case the shaft I3 carries a pinion I 4 meshing with an operating rack I5 which terminates in an operating arm I6 slidably extended out through a bearing I! in the case I0. An an- 15 chor arm I8 is extended from the Case ID oppositely to the operating arm I5 and has a series of spaced apertures I9 while the other arm I6 has a single aperture 20 near its ends as shown.

The spread ends I and la of the legs are con- 80 nected to these arms I5 and I8, one end being pivoted by a cotter key M or the like to the aperture 2|] in the operating arm I6 while the other end la is similarly mounted by a key 22 to any one of the apertures I9 in the anchor arm I8.

A smal hair spring 23 within the case I0 is connected to the pointer shaft I3 to normally hold the pointer I2 to zero position on the scale and a light expansion coil spring 25 is placed over the operating arm I6 and braced between the case and leg end I to take the play out of the pivotal connection therebetween. A larger and stronger retractile coil spring 25 is hooked at-its ends 22 in apertures 21 in the other ends 5 of the legs to normally draw these ends together.

Now as the work engaging ends 5 of the legs I and 2 are pulled apart to slip over the crankshaft C the opposite ends I and Ta are forced together and the resultant inward movement of the operating arm I6 swings the pointer I2 over the scale II through the action of the pinion M and rack I 5. The pointer thus registers the diameter of the crankshaft if the scale is properly graduated. However, the main function of the instrument is to detect and indicate flatness or unevenness of the crankshaft and it will be readily understood that with the work engaging ends 5 arranged as shown any irregularities in the crankshaft will be indicated by the pointer I2 as the crankshaft is slowly rotated.

The foregoing shape and formation of the legs I and 2 provides sharp inwardly directed U-bends 28 which strenghtens the arms greatly and allows the use of relatively light material. These bends 28 are preferably laterally and oppositely offset when they overlie one another whereby the remaining portions of the legs lie in the same plane. The capacity or range of the instrument may be varied by adjusting the leg end la to other apertures in the anchor arm l8.

While I have herein set forth a certain preferred embodiment of my invention, it is understood that I may vary from the same in minor structural details, so as best to construct a practical device for the purpose intended, not departing from the spirit of the invention and within the scope of the appended claims.

I claim: 7

1. In a device of the kind described, a pair of leg members pivotally connected at intermediate points, the said leg members being bowed oppositely and outwardly at one end, the other ends being spread apart, an indicating device comprising a case, a pointer provided on the case, a rack member for operating the pointer and arms oppositely extended from the rack member and case, one or the spread ends of the leg members being pivoted to the arm extended from the rack member, and the other spread end being adjustably connected to the arm extended from the case.

2. In a device of the kind described, a pair of leg members pivotally connected at intermediate points, the said leg members being bowed oppositely and outwardly at one end, the other ends being spread apart, an indicating device comprising a case, a pointer provided on the case, a rack member for operating the pointer and arms oppositely extended from the rack member and case, one of the spread ends of the leg members being pivoted to the arm extended from the rack member, and the other spread end being adjustably connected to the arm extended from the case, the said bowed ends of the leg members being turned inwardly and tapered to points at their extremities to engage the work, and a coil spring stretched between the said bowed ends to normally pull the same together.

GUY F. LONG; 

